The present invention relates to a suspension spring device for an automotive vehicle utilizing coil springs, in particular interrelationship, to attain a variable spring constant of the suspension system.
Generally, the suspension system of an automotive vehicle, where coil springs are utilized, is substantially constant. For this reason, a vehicle will typically ride hard where the number of passengers are small in number, and soft in instances where the passengers are large in number. It has however been found that an acute bump of the spring damper will not only give rise to an upward thrust phenomenon relative to the vehicle body but will also induce a change in attitude of the auto body and the consequent loss in stability of the vehicle. Consequently, the conventional suspension spring, with its constant spring constant, fails to satisfy needs for both comfort and performance in a car, without regard to the actual number of passengers therein.
The present invention may be viewed as a response to the above existent problems in the prior art.